1. Technical Field
This invention relates to balanced doors which pivot around medially inset vertical axes. More particularly, this invention relates to an operating mechanism for a balanced door which moves the door in a balanced manner without requiring a separate guide track along the door frame and interfitting guide roller on the door. The balanced door of the present invention is particularly suited for use as the door of an aircraft lavatory or the like.
2. Description of the Prior Art
Balanced doors are characterized by the balance between that part of the door which swings inwardly from the door frame and that part of the door which swings outwardly from the frame. Balanced doors are preferred where space limitations prevent the use of conventional doors pivoted on butt or other leaved hinges. Conventional doors require clearance for the full width of the door to swing inwardly or outwardly from the door frame.
A balanced door pivots around a medially inset axis so that one side portion of the door swings inwardly from the door frame while the other side portion of the door swings outwardly from the frame. Balanced doors are generally disclosed in Ellison U.S. Pat. No. 2,019,527, Lutter U.S. Pat. No. 2,768,409, Catlett et al. U.S. Pat. No. 3,605,339 and Wikkerink et al. U.S. Pat. No. 4,286,411. Until now, balanced movement of a door could be obtained only by providing a guide roller extending upwardly from the upper end of the door and engaging a downwardly opening guide track inset into or affixed to the header of the door frame. Such guide tracks and rollers necessarily complicate installation of the door. In some instances the door frame may not admit installation of the guide track, preventing use of a balanced door.